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González-Reyes M, Aragón J, Sánchez-Trujillo A, Rodríguez-Martínez G, Duarte K, Eleftheriou E, Barnier JV, Naquin D, Thermes C, Romo-Yáñez J, Roger JE, Rendon A, Vaillend C, Montanez C. Expression of Dystrophin Dp71 Splice Variants Is Temporally Regulated During Rodent Brain Development. Mol Neurobiol 2024:10.1007/s12035-024-04232-2. [PMID: 38802640 DOI: 10.1007/s12035-024-04232-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 05/13/2024] [Indexed: 05/29/2024]
Abstract
Dystrophin Dp71 is the major product of the Duchenne muscular dystrophy (DMD) gene in the brain, and its loss in DMD patients and mouse models leads to cognitive impairments. Dp71 is expressed as a range of proteins generated by alternative splicing of exons 71 to 74 and 78, classified in the main Dp71d and Dp71f groups that contain specific C-terminal ends. However, it is unknown whether each isoform has a specific role in distinct cell types, brain regions, and/or stages of brain development. In the present study, we characterized the expression of Dp71 isoforms during fetal (E10.5, E15.5) and postnatal (P1, P7, P14, P21 and P60) mouse and rat brain development. We finely quantified the expression of several Dp71 transcripts by RT-PCR and cloning assays in samples from whole-brain and distinct brain structures. The following Dp71 transcripts were detected: Dp71d, Dp71d∆71, Dp71d∆74, Dp71d∆71,74, Dp71d∆71-74, Dp71f, Dp71f∆71, Dp71f∆74, Dp71f∆71,74, and Dp71fΔ71-74. We found that the Dp71f isoform is the main transcript expressed at E10.5 (> 80%), while its expression is then progressively reduced and replaced by the expression of isoforms of the Dp71d group from E15.5 to postnatal and adult ages. This major finding was confirmed by third-generation nanopore sequencing. In addition, we found that the level of expression of specific Dp71 isoforms varies as a function of postnatal stages and brain structure. Our results suggest that Dp71 isoforms have different and complementary roles during embryonic and postnatal brain development, likely taking part in a variety of maturation processes in distinct cell types.
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Affiliation(s)
- Mayram González-Reyes
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Mexico City, Mexico
- Institut des Neurosciences Paris Saclay, Université Paris-Saclay, CNRS, Saclay, 91400, France
| | - Jorge Aragón
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Mexico City, Mexico
- Institut de la Vision, Sorbonne Université-INSERM-CNRS, 17 rue Moreau, Paris, 75012, France
| | - Alejandra Sánchez-Trujillo
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Mexico City, Mexico
| | - Griselda Rodríguez-Martínez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Mexico City, Mexico
- Laboratorio de Investigación en Inmunología y Proteómica, Hospital Infantil de México Federico Gómez, Mexico City, Mexico
| | - Kevin Duarte
- Institut des Neurosciences Paris Saclay, Université Paris-Saclay, CNRS, Saclay, 91400, France
| | - Evangelia Eleftheriou
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, 91198, France
| | - Jean-Vianney Barnier
- Institut des Neurosciences Paris Saclay, Université Paris-Saclay, CNRS, Saclay, 91400, France
| | - Delphine Naquin
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, 91198, France
| | - Claude Thermes
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, 91198, France
| | - José Romo-Yáñez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Mexico City, Mexico
- Institut de la Vision, Sorbonne Université-INSERM-CNRS, 17 rue Moreau, Paris, 75012, France
- Coordinación de Endocrinología Ginecológica y Perinatal, Instituto Nacional de Perinatología, Mexico City, Mexico
| | - Jérome E Roger
- Institut des Neurosciences Paris Saclay, Université Paris-Saclay, CNRS, Saclay, 91400, France
- CERTO-Retina France, Saclay, 91400, France
| | - Alvaro Rendon
- Institut de la Vision, Sorbonne Université-INSERM-CNRS, 17 rue Moreau, Paris, 75012, France
| | - Cyrille Vaillend
- Institut des Neurosciences Paris Saclay, Université Paris-Saclay, CNRS, Saclay, 91400, France.
| | - Cecilia Montanez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Mexico City, Mexico.
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Rugerio-Martínez CI, Ramos D, Segura-Olvera A, Murillo-Melo NM, Tapia-Guerrero YS, Argüello-García R, Leyva-García N, Hernández-Hernández O, Cisneros B, Suárez-Sánchez R. Dp71 Point Mutations Induce Protein Aggregation, Loss of Nuclear Lamina Integrity and Impaired Braf35 and Ibraf Function in Neuronal Cells. Int J Mol Sci 2022; 23:ijms231911876. [PMID: 36233175 PMCID: PMC9570083 DOI: 10.3390/ijms231911876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 10/04/2022] [Accepted: 10/04/2022] [Indexed: 11/16/2022] Open
Abstract
Dystrophin Dp71 is the most abundant product of the Duchenne muscular dystrophy gene in the nervous system, and mutations impairing its function have been associated with the neurodevelopmental symptoms present in a third of DMD patients. Dp71 is required for the clustering of neurotransmitter receptors and the neuronal differentiation of cultured cells; nonetheless, its precise role in neuronal cells remains to be poorly understood. In this study, we analyzed the effect of two pathogenic DMD gene point mutations on the Dp71 function in neurons. We engineered C272Y and E299del mutations to express GFP-tagged Dp71 protein variants in N1E-115 and SH-SY5Y neuronal cells. Unexpectedly, the ectopic expression of Dp71 mutants resulted in protein aggregation, which may be mechanistically caused by the effect of the mutations on Dp71 structure, as predicted by protein modeling and molecular dynamics simulations. Interestingly, Dp71 mutant variants acquired a dominant negative function that, in turn, dramatically impaired the distribution of different Dp71 protein partners, including β-dystroglycan, nuclear lamins A/C and B1, the high-mobility group (HMG)-containing protein (BRAF35) and the BRAF35-family-member inhibitor of BRAF35 (iBRAF). Further analysis of Dp71 mutants provided evidence showing a role for Dp71 in modulating both heterochromatin marker H3K9me2 organization and the neuronal genes’ expression, via its interaction with iBRAF and BRAF5.
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Affiliation(s)
- Claudia Ivette Rugerio-Martínez
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de Mexico 14389, Mexico
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de Mexico 07360, Mexico
| | - Daniel Ramos
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de Mexico 14389, Mexico
| | - Abel Segura-Olvera
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de Mexico 14389, Mexico
| | - Nadia Mireya Murillo-Melo
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de Mexico 14389, Mexico
| | - Yessica Sarai Tapia-Guerrero
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de Mexico 14389, Mexico
| | - Raúl Argüello-García
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de Mexico 07360, Mexico
| | - Norberto Leyva-García
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de Mexico 14389, Mexico
| | - Oscar Hernández-Hernández
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de Mexico 14389, Mexico
| | - Bulmaro Cisneros
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de Mexico 07360, Mexico
| | - Rocío Suárez-Sánchez
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de Mexico 14389, Mexico
- Correspondence: or ; Tel.: +52-55-5999-1000 (ext. 14710)
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Overexpression of the dystrophins Dp40 and Dp40 L170P modifies neurite outgrowth and the protein expression profile of PC12 cells. Sci Rep 2022; 12:1410. [PMID: 35082358 PMCID: PMC8791958 DOI: 10.1038/s41598-022-05271-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 01/04/2022] [Indexed: 11/08/2022] Open
Abstract
Dp40 is ubiquitously expressed including the central nervous system. In addition to being present in the nucleus, membrane, and cytoplasm, Dp40 is detected in neurites and postsynaptic spines in hippocampal neurons. Although Dp40 is expressed from the same promoter as Dp71, its role in the cognitive impairment present in Duchenne muscular dystrophy patients is still unknown. Here, we studied the effects of overexpression of Dp40 and Dp40L170P during the neuronal differentiation of PC12 Tet-On cells. We found that Dp40 overexpression increased the percentage of PC12 cells with neurites and neurite length, while Dp40L170P overexpression decreased them compared to Dp40 overexpression. Two-dimensional gel electrophoresis analysis showed that the protein expression profile was modified in nerve growth factor-differentiated PC12-Dp40L170P cells compared to that of the control cells (PC12 Tet-On). The proteins α-internexin and S100a6, involved in cytoskeletal structure, were upregulated. The expression of vesicle-associated membrane proteins increased in differentiated PC12-Dp40 cells, in contrast to PC12-Dp40L170P cells, while neurofilament light-chain was decreased in both differentiated cells. These results suggest that Dp40 has an important role in the neuronal differentiation of PC12 cells through the regulation of proteins involved in neurofilaments and exocytosis of synaptic vesicles, functions that might be affected in PC12-Dp40L170P.
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Di Paolo A, Eastman G, Mesquita-Ribeiro R, Farias J, Macklin A, Kislinger T, Colburn N, Munroe D, Sotelo Sosa JR, Dajas-Bailador F, Sotelo-Silveira JR. PDCD4 regulates axonal growth by translational repression of neurite growth-related genes and is modulated during nerve injury responses. RNA (NEW YORK, N.Y.) 2020; 26:1637-1653. [PMID: 32747606 PMCID: PMC7566564 DOI: 10.1261/rna.075424.120] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 07/20/2020] [Indexed: 05/07/2023]
Abstract
Programmed cell death 4 (PDCD4) protein is a tumor suppressor that inhibits translation through the mTOR-dependent initiation factor EIF4A, but its functional role and mRNA targets in neurons remain largely unknown. Our work identified that PDCD4 is highly expressed in axons and dendrites of CNS and PNS neurons. Using loss- and gain-of-function experiments in cortical and dorsal root ganglia primary neurons, we demonstrated the capacity of PDCD4 to negatively control axonal growth. To explore PDCD4 transcriptome and translatome targets, we used Ribo-seq and uncovered a list of potential targets with known functions as axon/neurite outgrowth regulators. In addition, we observed that PDCD4 can be locally synthesized in adult axons in vivo, and its levels decrease at the site of peripheral nerve injury and before nerve regeneration. Overall, our findings demonstrate that PDCD4 can act as a new regulator of axonal growth via the selective control of translation, providing a target mechanism for axon regeneration and neuronal plasticity processes in neurons.
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Affiliation(s)
- Andrés Di Paolo
- Departamento de Proteínas y Ácidos Nucleicos, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay
| | - Guillermo Eastman
- Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay
| | | | - Joaquina Farias
- Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay
| | - Andrew Macklin
- Princess Margaret Cancer Centre, University Health Network, Toronto M5G 1L7, Canada
| | - Thomas Kislinger
- Princess Margaret Cancer Centre, University Health Network, Toronto M5G 1L7, Canada
- University of Toronto, Department of Medical Biophysics, Toronto M5S 1A1, Canada
| | - Nancy Colburn
- Former Chief of Laboratory of Cancer Prevention at the National Cancer Institute-NIH at Frederick, Maryland 21702, USA
| | - David Munroe
- Former Laboratory of Molecular Technologies, LEIDOS at Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, USA
| | - José R Sotelo Sosa
- Departamento de Proteínas y Ácidos Nucleicos, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay
| | | | - José R Sotelo-Silveira
- Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay
- Departamento de Biología Celular y Molecular, Facultad de Ciencias UdelaR, Montevideo 11400, Uruguay
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Naidoo M, Anthony K. Dystrophin Dp71 and the Neuropathophysiology of Duchenne Muscular Dystrophy. Mol Neurobiol 2020; 57:1748-1767. [PMID: 31836945 PMCID: PMC7060961 DOI: 10.1007/s12035-019-01845-w] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 11/22/2019] [Indexed: 12/13/2022]
Abstract
Duchenne muscular dystrophy (DMD) is caused by frameshift mutations in the DMD gene that prevent the body-wide translation of its protein product, dystrophin. Besides a severe muscle phenotype, cognitive impairment and neuropsychiatric symptoms are prevalent. Dystrophin protein 71 (Dp71) is the major DMD gene product expressed in the brain and mutations affecting its expression are associated with the DMD neuropsychiatric syndrome. As with dystrophin in muscle, Dp71 localises to dystrophin-associated protein complexes in the brain. However, unlike in skeletal muscle; in the brain, Dp71 is alternatively spliced to produce many isoforms with differential subcellular localisations and diverse cellular functions. These include neuronal differentiation, adhesion, cell division and excitatory synapse organisation as well as nuclear functions such as nuclear scaffolding and DNA repair. In this review, we first describe brain involvement in DMD and the abnormalities observed in the DMD brain. We then review the gene expression, RNA processing and functions of Dp71. We review genotype-phenotype correlations and discuss emerging cellular/tissue evidence for the involvement of Dp71 in the neuropathophysiology of DMD. The literature suggests changes observed in the DMD brain are neurodevelopmental in origin and that their risk and severity is associated with a cumulative loss of distal DMD gene products such as Dp71. The high risk of neuropsychiatric syndromes in Duchenne patients warrants early intervention to achieve the best possible quality of life. Unravelling the function and pathophysiological significance of dystrophin in the brain has become a high research priority to inform the development of brain-targeting treatments for Duchenne.
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Affiliation(s)
- Michael Naidoo
- Centre for Physical Activity and Life Sciences, Faculty of Arts, Science and Technology, University of Northampton, University Drive, Northampton, Northamptonshire, NN1 5PH, UK
| | - Karen Anthony
- Centre for Physical Activity and Life Sciences, Faculty of Arts, Science and Technology, University of Northampton, University Drive, Northampton, Northamptonshire, NN1 5PH, UK.
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Ruggieri S, De Giorgis M, Annese T, Tamma R, Notarangelo A, Marzullo A, Senetta R, Cassoni P, Notarangelo M, Ribatti D, Nico B. Dp71 Expression in Human Glioblastoma. Int J Mol Sci 2019; 20:E5429. [PMID: 31683640 PMCID: PMC6862465 DOI: 10.3390/ijms20215429] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 10/14/2019] [Accepted: 10/30/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Dp71 is the most abundant dystrophin (DMD) gene product in the nervous system. Mutation in the Dp71 coding region is associated with cognitive disturbances in Duchenne muscular dystrophy (DMD) patients, but the function of dystrophin Dp71 in tumor progression remains to be established. This study investigated Dp71 expression in glioblastoma, the most common and aggressive primary tumor of the central nervous system (CNS). METHODS Dp71 expression was analyzed by immunofluorescence, immunohistochemistry, RT-PCR, and immunoblotting in glioblastoma cell lines and cells isolated from human glioblastoma multiforme (GBM) bioptic specimens. RESULTS Dp71 isoform was expressed in normal human astrocytes (NHA) cell lines and decreased in glioblastoma cell lines and cells isolated from human glioblastoma multiforme bioptic specimens. Moreover, Dp71 was localized in the nucleus in normal cells, while it was localized into the cytoplasm of glioblastoma cells organized in clusters. We have shown, by double labeling, that Dp71 colocalizes with lamin B in normal astrocytes cells, confirming the roles of Dp71 and lamin B in maintaining nuclear architecture. Finally, we demonstrated that decreased Dp71 protein in cells isolated from human bioptic specimens was inversely correlated with the Ki-67 tumor proliferative index. CONCLUSION A decreased Dp71 expression is associated with cancer proliferation and poor prognosis in glioblastoma.
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Affiliation(s)
- Simona Ruggieri
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy.
| | - Michelina De Giorgis
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy.
| | - Tiziana Annese
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy.
| | - Roberto Tamma
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy.
| | - Angelo Notarangelo
- Medical Genetic Unit, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, 71013 Foggia, Italy.
| | - Andrea Marzullo
- Department of Emergency and Transplantation, Pathology Unit, University of Bari Medical School, 70124 Bari, Italy.
| | - Rebecca Senetta
- Pathology Unit, Department of Medical Sciences, University of Turin, University of Turin Medical School, 10124 Turin, Italy.
| | - Paola Cassoni
- Pathology Unit, Department of Medical Sciences, University of Turin, University of Turin Medical School, 10124 Turin, Italy.
| | - Michela Notarangelo
- Centre for Integrative Biology, CIBIO, University of Trento, 38123 Trento, Italy.
| | - Domenico Ribatti
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy.
| | - Beatrice Nico
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy.
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The dystrophin isoform Dp71e Δ71 is involved in neurite outgrowth and neuronal differentiation of PC12 cells. J Proteomics 2018; 191:80-87. [PMID: 29625189 DOI: 10.1016/j.jprot.2018.03.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 03/19/2018] [Accepted: 03/25/2018] [Indexed: 11/22/2022]
Abstract
The Dp71 protein is the most abundant dystrophin in the central nervous system (CNS). Several dystrophin Dp71 isoforms have been described and are classified into three groups, each with a different C-terminal end. However, the functions of Dp71 isoforms remain unknown. In the present study, we analysed the effect of Dp71eΔ71 overexpression on neuronal differentiation of PC12 Tet-On cells. Overexpression of dystrophin Dp71eΔ71 stimulates neuronal differentiation, increasing the percentage of cells with neurites and neurite length. According to 2-DE analysis, Dp71eΔ71 overexpression modified the protein expression profile of rat pheochromocytoma PC12 Tet-On cells that had been treated with neuronal growth factor (NGF) for nine days. Interestingly, all differentially expressed proteins were up-regulated compared to the control. The proteomic analysis showed that Dp71eΔ71 increases the expression of proteins with important roles in the differentiation process, such as HspB1, S100A6, and K8 proteins involved in the cytoskeletal structure and HCNP protein involved in neurotransmitter synthesis. The expression of neuronal marker TH was also up-regulated. Mass spectrometry data are available via ProteomeXchange with identifier PXD009114. SIGNIFICANCE: This study is the first to explore the role of the specific isoform Dp71eΔ71. The results obtained here support the hypothesis that the dystrophin Dp71eΔ71 isoform has an important role in the neurite outgrowth by regulating the levels of proteins involved in the cytoskeletal structure, such as HspB1, S100A6, and K8, and in neurotransmitter synthesis, such as HCNP and TH, biological processes required to stimulate neuronal differentiation.
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Becerril-Esquivel C, Peñuelas-Urquides K, Blancas-Sánchez E, Zapata-Benavides P, Silva-Ramírez B, Chávez-Reyes A, Castorena-Torres F, Cisneros B, Bermúdez de León M. The polyaromatic hydrocarbon β-naphthoflavone alters binding of YY1, Sp1, and Sp3 transcription factors to the Dp71 promoter in hepatic cells. Mol Med Rep 2018; 17:6150-6155. [PMID: 29484433 DOI: 10.3892/mmr.2018.8626] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 01/19/2018] [Indexed: 11/06/2022] Open
Abstract
The smallest product of the Duchenne muscular dystrophy gene, dystrophin (Dp)71, is ubiquitously expressed in nonmuscle tissues. We previously showed that Dp71 expression in hepatic cells is modulated in part by stimulating factor 1 (Sp1), stimulating protein 3 (Sp3), and yin yang 1 (YY1) transcription factors, and that the polyaromatic hydrocarbon, β-naphthoflavone (β‑NF), downregulates Dp71 expression. The aim of the present study was to determine whether β‑NF represses Dp71 expression by altering mRNA stability or its promoter activity. Reverse transcription‑quantitative polymerase chain reaction was used to measure half‑life mRNA levels in β‑NF‑treated cells exposed to actinomycin D, an inhibitor of transcription, for 0, 4, 8, 12 and 16 h. Transient transfections with a plasmid carrying the Dp71 basal promoter fused to luciferase reporter gene were carried out in control and β‑NF‑treated cells. Electrophoretic mobility shift assays (EMSAs) were performed with labeled probes, corresponding to Dp71 promoter sequences, and nuclear extracts of control and β‑NF‑treated cells. To the best of our knowledge, the results demonstrated for the first time that this negative regulation takes place at the promoter level rather than the mRNA stability level. Interestingly, using EMSAs, β‑NF reduced binding of YY1, Sp1, and Sp3 to the Dp71 promoter. It also suggests that β‑NF may modulate the expression of other genes regulated by these transcription factors. In conclusion, β‑NF represses Dp71 expression in hepatic cells by altering binding of YY1, Sp1, and Sp3 to the Dp71 promoter.
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Affiliation(s)
- Carolina Becerril-Esquivel
- Departamento de Biología Molecular, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León 64720, México
| | - Katia Peñuelas-Urquides
- Departamento de Biología Molecular, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León 64720, México
| | - Erik Blancas-Sánchez
- Departamento de Biología Molecular, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León 64720, México
| | - Pablo Zapata-Benavides
- Universidad Autónoma de Nuevo León, UANL, Facultad de Ciencias Biológicas, San Nicolás de los Garza, Nuevo León 66451, México
| | - Beatriz Silva-Ramírez
- Departamento de Inmunogenética, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León 64720, México
| | - Arturo Chávez-Reyes
- Centro de Investigación y de Estudios Avanzados del IPN Unidad Monterrey, Apodaca, Nuevo León 66600, México
| | | | - Bulmaro Cisneros
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN unidad Zacatenco, Ciudad de México 07360, México
| | - Mario Bermúdez de León
- Departamento de Biología Molecular, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León 64720, México
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Tan S, Tan J, Tan S, Zhao S, Cao X, Chen Z, Weng Q, Zhang H, Wang K, Zhou J, Xiao X. Decreased Dp71 expression is associated with gastric adenocarcinoma prognosis. Oncotarget 2018; 7:53702-53711. [PMID: 27449096 PMCID: PMC5288215 DOI: 10.18632/oncotarget.10724] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 07/06/2016] [Indexed: 11/25/2022] Open
Abstract
For the first time, dramatically decreased Dp71 protein and mRNA was found in 34 pairs of resected primary gastric adenocarcinoma. Immunohistochemistry identified Dp71 expression suppressed in 72.2% of 104 gastric cancer patients. The decreased Dp71 expression was significantly correlated with cancer differentiation (P=0.001) and lymph vascular invasion (p=0.041). Decreased Dp71 expression was associated with a poor gastric adenocarcinoma prognosis (P=0.001). Significantly less Dp71 mRNA and protein were found in BGC823, SGC7901, AGS compared with GES-1. Via increasing lamin B1 mRNA and protein, enforced Dp71d and Dp71f expression resulted in SGC7901 proliferation inhibition. Co-IP proved interaction of Dp71 with lamin B1 in GES-1 cells. Further expression characterization showed reduced lamin B1 in gastric cancer tissue and cancer cells. Increasing lamin B1 expression results in the growth inhibition of SGC7901, which suggests that Dp71-lamin B1 protein complex plays an important role for the newly identified tumor suppressive function of Dp71.
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Affiliation(s)
- Sipin Tan
- Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410008, People's Republic of China
| | - Jin Tan
- Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410008, People's Republic of China
| | - Sichuang Tan
- Department of Thoracic Surgery, Second Xiangya Hospital, Central South University, Hunan 410011, People's Republic of China
| | - Shuai Zhao
- Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410008, People's Republic of China
| | - Xiaoxia Cao
- Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410008, People's Republic of China
| | - Zhikang Chen
- Department of General Surgery, Xiangya Hospital, Central South University, Changsha 410008, People's Republic of China
| | - Qiaocheng Weng
- Department of General Surgery, Xiangya Hospital, Central South University, Changsha 410008, People's Republic of China
| | - Huali Zhang
- Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410008, People's Republic of China
| | - Kangkai Wang
- Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410008, People's Republic of China
| | - Jiang Zhou
- Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410008, People's Republic of China
| | - Xianzhong Xiao
- Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410008, People's Republic of China
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10
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Dystrophin Dp71 Isoforms Are Differentially Expressed in the Mouse Brain and Retina: Report of New Alternative Splicing and a Novel Nomenclature for Dp71 Isoforms. Mol Neurobiol 2017; 55:1376-1386. [PMID: 28127699 DOI: 10.1007/s12035-017-0405-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Accepted: 01/12/2017] [Indexed: 12/27/2022]
Abstract
Multiple dystrophin Dp71 isoforms have been identified in rats, mice, and humans and in several cell line models. These Dp71 isoforms are produced by the alternative splicing of exons 71 to 74 and 78 and intron 77. Three main groups of Dp71 proteins are defined based on their C-terminal specificities: Dp71d, Dp71f, and Dp71e. Dp71 is highly expressed in the brain and retina; however, the specific isoforms present in these tissues have not been determined to date. In this work, we explored the expression of Dp71 isoforms in the mouse brain and retina using RT-PCR assays followed by the cloning of PCR products into the pGEM-T Easy vector, which was used to transform DH5α cells. Dp71-positive colonies were later analyzed by PCR multiplex and DNA sequencing to determine the alternative splicing. We thus demonstrated the expression of Dp71 transcripts corresponding to Dp71, Dp71a, Dp71c, Dp71b, Dp71ab, Dp71 Δ110, and novel Dp71 isoforms spliced in exon 74; 71 and 74; 71, 73 and 74; and 74 and 78, which we named Dp71d Δ74 , Dp71d Δ71,74 , Dp71d Δ71,73-74 , and Dp71f Δ74 , respectively. Additionally, we demonstrated that the Dp71d group of isoforms is highly expressed in the brain, while the Dp71f group predominates in the retina, at both the cDNA and protein levels. These findings suggest that distinct Dp71 isoforms may play different roles in the brain and retina.
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11
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Transcription factors YY1, Sp1 and Sp3 modulate dystrophin Dp71 gene expression in hepatic cells. Biochem J 2016; 473:1967-76. [PMID: 27143785 DOI: 10.1042/bcj20160163] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 05/03/2016] [Indexed: 11/17/2022]
Abstract
Dystrophin Dp71, the smallest product encoded by the Duchenne muscular dystrophy gene, is ubiquitously expressed in all non-muscle cells. Although Dp71 is involved in various cellular processes, the mechanisms underlying its expression have been little studied. In hepatic cells, Dp71 expression is down-regulated by the xenobiotic β-naphthoflavone. However, the effectors of this regulation remain unknown. In the present study we aimed at identifying DNA elements and transcription factors involved in Dp71 expression in hepatic cells. Relevant DNA elements on the Dp71 promoter were identified by comparing Dp71 5'-end flanking regions between species. The functionality of these elements was demonstrated by site-directed mutagenesis. Using EMSAs and ChIP, we showed that the Sp1 (specificity protein 1), Sp3 (specificity protein 3) and YY1 (Yin and Yang 1) transcription factors bind to the Dp71 promoter region. Knockdown of Sp1, Sp3 and YY1 in hepatic cells increased endogenous Dp71 expression, but reduced Dp71 promoter activity. In summary, Dp71 expression in hepatic cells is carried out, in part, by YY1-, Sp1- and Sp3-mediated transcription from the Dp71 promoter.
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12
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Nishida A, Yasuno S, Takeuchi A, Awano H, Lee T, Niba ETE, Fujimoto T, Itoh K, Takeshima Y, Nishio H, Matsuo M. HEK293 cells express dystrophin Dp71 with nucleus-specific localization of Dp71ab. Histochem Cell Biol 2016; 146:301-9. [PMID: 27109495 DOI: 10.1007/s00418-016-1439-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2016] [Indexed: 11/30/2022]
Abstract
The dystrophin gene consists of 79 exons and encodes tissue-specific isoforms. Mutations in the dystrophin gene cause Duchenne muscular dystrophy, of which a substantial proportion of cases are complicated by non-progressive mental retardation. Abnormalities of Dp71, an isoform transcribed from a promoter in intron 62, are a suspected cause of mental retardation. However, the roles of Dp71 in human brain have not been fully elucidated. Here, we characterized dystrophin in human HEK293 cells with the neuronal lineage. Reverse transcription-PCR amplification of the full-length dystrophin transcript revealed the absence of fragments covering the 5' part of the dystrophin cDNA. In contrast, fragments covering exons 64-79 were present. The Dp71 promoter-specific exon G1 was shown spliced to exon 63. We demonstrated that the Dp71 transcript comprised two subisoforms: one lacking exon 78 (Dp71b) and the other lacking both exons 71 and 78 (Dp71ab). Western blotting of cell lysates using an antibody against the dystrophin C-terminal region revealed two bands, corresponding to Dp71b and Dp71ab. Immunohistochemical examination with the dystrophin antibody revealed scattered punctate signals in the cytoplasm and the nucleus. Western blotting revealed one band corresponding to Dp71b in the cytoplasm and two bands corresponding to Dp71b and Dp71ab in the nucleus, with Dp71b being predominant. These results indicated that Dp71ab is a nucleus-specific subisoform. We concluded that Dp71, comprising Dp71b and Dp71ab, was expressed exclusively in HEK293 cells and that Dp71ab was specifically localized to the nucleus. Our findings suggest that Dp71ab in the nucleus contributes to the diverse functions of HEK293 cells.
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Affiliation(s)
- Atsushi Nishida
- Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani, Nishi, Kobe, 651-2180, Japan
| | - Sato Yasuno
- Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani, Nishi, Kobe, 651-2180, Japan.,Kobe Pharmaceutical University, Higashinada, Kobe, 658-8558, Japan
| | - Atsuko Takeuchi
- Kobe Pharmaceutical University, Higashinada, Kobe, 658-8558, Japan
| | - Hiroyuki Awano
- Department of Pediatrics, Graduate School of Medicine, Kobe University, Chuo, Kobe, 650-0017, Japan
| | - Tomoko Lee
- Department of Pediatrics, Hyogo College of Medicine, Mukogawacho, Nishinomiya, 663-8501, Japan
| | - Emma Tabe Eko Niba
- Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani, Nishi, Kobe, 651-2180, Japan
| | - Takahiro Fujimoto
- Department of Pathology and Applied Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Kyoko Itoh
- Department of Pathology and Applied Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Yasuhiro Takeshima
- Department of Pediatrics, Hyogo College of Medicine, Mukogawacho, Nishinomiya, 663-8501, Japan
| | - Hisahide Nishio
- Department of Community Medicine and Social Healthcare Science, Graduate School of Medicine, Kobe University, Chuo, Kobe, 650-0017, Japan
| | - Masafumi Matsuo
- Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani, Nishi, Kobe, 651-2180, Japan.
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Merino-Jiménez C, Aragón J, Ceja V, Rodríguez-Martínez G, Cázares-Raga FE, Chardonnet S, Pionneau C, Rendon A, Montañez C. Dp71Δ78-79 dystrophin mutant stimulates neurite outgrowth in PC12 cells via upregulation and phosphorylation of HspB1. Proteomics 2016; 16:1331-40. [PMID: 26936078 DOI: 10.1002/pmic.201500211] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 01/24/2016] [Accepted: 02/29/2016] [Indexed: 11/05/2022]
Abstract
PC12 cells acquire a neuronal phenotype in response to nerve growth factor (NGF). However, this phenotype is more efficiently achieved when the Dp71Δ78-79 dystrophin mutant is stably expressed in PC12-C11 cells. To investigate the effect of Dp71Δ78-79 overexpression on the protein profile of PC12-C11 cells, we compared the expression profiles of undifferentiated and NGF-differentiated PC12-C11 and PC12 cells by 2DE. In undifferentiated cultures, one protein was downregulated, and five were upregulated. Dp71Δ78-79 overexpression had a greater effect on differentiated cultures, with ten proteins downregulated and seven upregulated. The protein with the highest upregulation was HspB1. Changes in HspB1 expression were validated by Western blot and immunofluorescence analyses. Interestingly, the neurite outgrowth in PC12-C11 cells was affected by a polyclonal antibody against HspB1, and the level of HspB1 and HspB1Ser86 decreased, suggesting an important role for this protein in this cellular process. Our results show that Dp71Δ78-79 affects the expression level of some proteins and that the stimulated neurite outgrowth produced by this mutant is mainly through upregulation and phosphorylation of HspB1.
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Affiliation(s)
- Candelaria Merino-Jiménez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN, México, D.F., México
| | - Jorge Aragón
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN, México, D.F., México
| | - Víctor Ceja
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN, México, D.F., México
| | - Griselda Rodríguez-Martínez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN, México, D.F., México
| | - Febe E Cázares-Raga
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, México, D.F., México
| | - Solenne Chardonnet
- UPMC Univ Paris 06, UMS 2 Omique, Sorbonne Universités, Plateforme P3S, Paris, France.,UMS 29 Omique, INSERM, Plateforme P3S, Paris, France
| | - Cédric Pionneau
- UPMC Univ Paris 06, UMS 2 Omique, Sorbonne Universités, Plateforme P3S, Paris, France.,UMS 29 Omique, INSERM, Plateforme P3S, Paris, France
| | - Alvaro Rendon
- Institut de la Vision, INSERM UMR_S968, CNRS UMR_7210, Université Pierre et Marie Curie Paris 06, Paris, France
| | - Cecilia Montañez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN, México, D.F., México
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14
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Giocanti-Auregan A, Vacca O, Bénard R, Cao S, Siqueiros L, Montañez C, Paques M, Sahel JA, Sennlaub F, Guillonneau X, Rendon A, Tadayoni R. Altered astrocyte morphology and vascular development in dystrophin-Dp71-null mice. Glia 2015; 64:716-29. [PMID: 26711882 DOI: 10.1002/glia.22956] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 11/28/2015] [Accepted: 12/02/2015] [Indexed: 01/14/2023]
Abstract
Understanding retinal vascular development is crucial because many retinal vascular diseases such as diabetic retinopathy (in adults) or retinopathy of prematurity (in children) are among the leading causes of blindness. Given the localization of the protein Dp71 around the retinal vessels in adult mice and its role in maintaining retinal homeostasis, the aim of this study was to determine if Dp71 was involved in astrocyte and vascular development regulation. An experimental study in mouse retinas was conducted. Using a dual immunolabeling with antibodies to Dp71 and anti-GFAP for astrocytes on retinal sections and isolated astrocytes, it was found that Dp71 was expressed in wild-type (WT) mouse astrocytes from early developmental stages to adult stage. In Dp71-null mice, a reduction in GFAP-immunopositive astrocytes was observed as early as postnatal day 6 (P6) compared with WT mice. Using real-time PCR, it was showed that Dp71 mRNA was stable between P1 and P6, in parallel with post-natal vascular development. Regarding morphology in Dp71-null and WT mice, a significant decrease in overall astrocyte process number in Dp71-null retinas at P6 to adult age was found. Using fluorescence-conjugated isolectin Griffonia simplicifolia on whole mount retinas, subsequent delay of developing vascular network at the same age in Dp71-null mice was found. An evidence that the Dystrophin Dp71, a membrane-associated cytoskeletal protein and one of the smaller Duchenne muscular dystrophy gene products, regulates astrocyte morphology and density and is associated with subsequent normal blood vessel development was provided.
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Affiliation(s)
- Audrey Giocanti-Auregan
- Ophthalmology Department, Avicenne Hospital, 125 Rue De Stalingrad, Bobigny, France.,Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Ophélie Vacca
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Romain Bénard
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Sijia Cao
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Lourdes Siqueiros
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Cecilia Montañez
- Department of Genetics & Molecular Biology, Research Centre for Advanced Studies, IPN, Av. I.P.N. 2508, Mexico City, C.P., 07360, Mexico
| | - Michel Paques
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France.,Centre Hospitalier National D'ophtalmologie Des Quinze-Vingts, DHU View Maintain, INSERM-DHOS CIC 1423, Paris, F-75012, France
| | - José-Alain Sahel
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France.,Centre Hospitalier National D'ophtalmologie Des Quinze-Vingts, DHU View Maintain, INSERM-DHOS CIC 1423, Paris, F-75012, France.,Fondation Ophtalmologique Rothschild, Paris, F-75019, France
| | - Florian Sennlaub
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Xavier Guillonneau
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Alvaro Rendon
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Ramin Tadayoni
- Institut De La Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S, 968, Paris, F-75012, France.,INSERM, U_968, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France.,Ophthalmology Department, Hôpital Lariboisière, AP-HP, University Paris 7, Sorbonne Paris Cité, 2 Rue Ambroise Paré, Paris, 75010, France
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15
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Tan S, Tan S, Chen Z, Cheng K, Chen Z, Wang W, Wen Q, Zhang W. Knocking down Dp71 expression in A549 cells reduces its malignancy in vivo and in vitro. Cancer Invest 2015; 34:16-25. [PMID: 26691328 DOI: 10.3109/07357907.2015.1084002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Dp71 is one of the most ubiquitously expressed isoforms of dystrophin, the pathological genes of DMD. In order to find whether the alteration of Dp71 can affect the phenotypes of cell other than PC12, an A549 cell line with stably transfected Dp71 siRNA plasmids was set up and named A549-Dp71AS cell. It is demonstrated for the first time that the A549-Dp71AS cell line displayed decreased invasion capabilities, reduced migration ability, decreased proliferation rate, and lessened clonogenic formation. Cisplatin-induced apoptosis was also increased in A549-Dp71AS cell line via enhancing the Caspase 3, Caspase 8, and Caspase 9 activities. Knocking down Dp71 expression can significantly inhibit the A549 xenograft tumor growth in nude mice. The A549-Dp71AS cells and xenograft tumor tissues displayed reduced lamin B1, Bcl-2, and MMP2 protein expression, which accounts for the reduced malignancy of A549-Dp71AS cells in vivo and in vitro.
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Affiliation(s)
- Sichuang Tan
- a Department of Thoracic Surgery, Second Xiangya Hospital , Central South University , Changsha , Hunan , China
| | - Sipin Tan
- b Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine , Central South University , Hunan , China
- c Molecular and Cell Experimental Center, Xiangya School of Medicine , Central South University , Changsha , Hunan , China
| | - Zhikang Chen
- d Department of General Surgery, Xiangya Hospital , Central South University , Hunan , China
| | - Ke Cheng
- e Center of Transplant Surgery, Third Xiangya Hospital , Central South University , Hunan , China
| | - Zhicao Chen
- e Center of Transplant Surgery, Third Xiangya Hospital , Central South University , Hunan , China
| | - Wenmei Wang
- b Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine , Central South University , Hunan , China
| | - Qiaocheng Wen
- d Department of General Surgery, Xiangya Hospital , Central South University , Hunan , China
| | - Weilin Zhang
- d Department of General Surgery, Xiangya Hospital , Central South University , Hunan , China
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16
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Tan J, Tan S, Zheng H, Liu M, Chen G, Zhang H, Wang K, Tan S, Zhou J, Xiao XZ. HSF1 functions as a transcription regulator for Dp71 expression. Cell Stress Chaperones 2015; 20:371-9. [PMID: 25430510 PMCID: PMC4326382 DOI: 10.1007/s12192-014-0558-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 11/13/2014] [Accepted: 11/17/2014] [Indexed: 11/25/2022] Open
Abstract
Heat shock factor 1 (HSF1) is one of the most important transcriptional molecules in the heat shock process; however, HSF1 can also regulate the expression of other proteins. Dystrophin Dp71 is one of the most widely expressed isoforms of the dystrophin gene family. In our experiments, we showed for the first time that HSF1 can function as a transcriptional factor for endogenous Dp71 expression in vivo and in vitro. We demonstrated that the messenger RNA (mRNA) and protein expression of Dp71 were significantly reduced in HSF1-knockout mice compared with wild-type mice in brain, lung, liver, spleen, and kidney. Overexpression of HSF1 significantly enhanced the mRNA and protein expression of Dp71 in HeLa cells. Inhibiting the expression of HSF1 in HeLa cells significantly reduced the expression of Dp71. By use of the EMSA technique, the chromatin immunoprecipitation assay, and the luciferase reporter system, we demonstrated that HSF1 can directly bind the HSE in the Dp71 promoter region. We concluded from our data that HSF1 functions as a transcriptional regulator of Dp71 expression.
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Affiliation(s)
- Jin Tan
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
| | - Sichuang Tan
- />Department of Thoracic and Cardiovascular Surgery, Second Xiangya Hospital, 139# Ren Ming Road, Changsha, Hunan 410011 People’s Republic of China
| | - Hexin Zheng
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
- />Key Laboratory of Genetics and Birth Health of Hunan Province, Family Planning, Institute of Hunan Province, Changsha, 410126 China
| | - Meidong Liu
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
| | - Guangwen Chen
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
| | - Huali Zhang
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
| | - Kangkai Wang
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
| | - Sipin Tan
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
- />Molecular and Cell Experimental Center, Xiangya School of Medicine, Central South University, Changsha, Hunan 410013 People’s Republic of China
| | - Jiang Zhou
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
| | - Xian-zhong Xiao
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
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17
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Rodríguez R, Hernández-Hernández O, Magaña JJ, González-Ramírez R, García-López ES, Cisneros B. Altered nuclear structure in myotonic dystrophy type 1-derived fibroblasts. Mol Biol Rep 2014; 42:479-88. [PMID: 25307018 DOI: 10.1007/s11033-014-3791-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 10/03/2014] [Indexed: 12/14/2022]
Abstract
Myotonic dystrophy type 1 (DM1) is a multisystem genetic disorder caused by a triplet nucleotide repeat expansion in the 3' untranslated region of the Dystrophia Myotonica-Protein Kinase (DMPK) gene. DMPK gene transcripts containing CUG expanded repeats accumulate in nuclear foci and ultimately cause altered splicing/gene expression of numerous secondary genes. The study of primary cell cultures derived from patients with DM1 has allowed the identification and further characterization of molecular mechanisms underlying the pathology in the natural context of the disease. In this study we show for the first time impaired nuclear structure in fibroblasts of DM1 patients. DM1-derived fibroblasts exhibited altered localization of the nuclear envelope (NE) proteins emerin and lamins A/C and B1 with concomitant increased size and altered shape of nuclei. Abnormal NE organization is more common in DM1 fibroblasts containing abundant nuclear foci, implying expression of the expanded RNA as determinant of nuclear defects. That transient expression of the DMPK 3' UTR containing 960 CTG but not with the 3' UTR lacking CTG repeats is sufficient to generate NE disruption in normal fibroblasts confirms the direct impact of mutant RNA on NE architecture. We also evidence nucleoli distortion in DM1 fibroblasts by immunostaining of the nucleolar protein fibrillarin, implying a broader effect of the mutant RNA on nuclear structure. In summary, these findings reveal that NE disruption, a hallmark of laminopathy disorders, is a novel characteristic of DM1.
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Affiliation(s)
- R Rodríguez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), Av. IPN 2508 Col Zacatenco, 07360, Mexico, D.F, Mexico
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18
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Suárez-Sánchez R, Aguilar A, Wagstaff KM, Velez G, Azuara-Medina PM, Gomez P, Vásquez-Limeta A, Hernández-Hernández O, Lieu KG, Jans DA, Cisneros B. Nucleocytoplasmic shuttling of the Duchenne muscular dystrophy gene product dystrophin Dp71d is dependent on the importin α/β and CRM1 nuclear transporters and microtubule motor dynein. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1843:985-1001. [PMID: 24486332 DOI: 10.1016/j.bbamcr.2014.01.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Revised: 12/17/2013] [Accepted: 01/24/2014] [Indexed: 01/08/2023]
Abstract
Even though the Duchenne muscular dystrophy (DMD) gene product Dystrophin Dp71d is involved in various key cellular processes through its role as a scaffold for structural and signalling proteins at the plasma membrane as well as the nuclear envelope, its subcellular trafficking is poorly understood. Here we map the nuclear import and export signals of Dp71d by truncation and point mutant analysis, showing for the first time that Dp71d shuttles between the nucleus and cytoplasm mediated by the conventional nuclear transporters, importin (IMP) α/β and the exportin CRM1. Binding was confirmed in cells using pull-downs, while in vitro binding assays showed direct, high affinity (apparent dissociation coefficient of c. 0.25nM) binding of Dp71d to IMPα/β. Interestingly, treatment of cells with the microtubule depolymerizing reagent nocodazole or the dynein inhibitor EHNA both decreased Dp71d nuclear localization, implying that Dp71d nuclear import may be facilitated by microtubules and the motor protein dynein. The role of Dp71d in the nucleus appears to relate in part to interaction with the nuclear envelope protein emerin, and maintenance of the integrity of the nuclear architecture. The clear implication is that Dp71d's previously unrecognised nuclear transport properties likely contribute to various, important physiological roles.
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Affiliation(s)
- R Suárez-Sánchez
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico; Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación, México D.F, Mexico
| | - A Aguilar
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - K M Wagstaff
- Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | - G Velez
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - P M Azuara-Medina
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - P Gomez
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - A Vásquez-Limeta
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - O Hernández-Hernández
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación, México D.F, Mexico
| | - K G Lieu
- Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | - D A Jans
- Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia.
| | - B Cisneros
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico.
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Dystrophin Dp71: The Smallest but Multifunctional Product of the Duchenne Muscular Dystrophy Gene. Mol Neurobiol 2011; 45:43-60. [DOI: 10.1007/s12035-011-8218-9] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 11/02/2011] [Indexed: 01/06/2023]
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20
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Saint Martín A, Aragón J, Depardon-Benítez F, Sánchez-Trujillo A, Mendoza-Hernández G, Ceja V, Montañez C. Identification of Dp71e, a new dystrophin with a novel carboxy-terminal end. FEBS J 2011; 279:66-77. [DOI: 10.1111/j.1742-4658.2011.08399.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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21
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Aragón J, Romo-Yáñez J, Martínez-Herrera A, Ceja V, Rendon A, Montañez C. Characterization of Dp71Δ(78-79), a novel dystrophin mutant that stimulates PC12 cell differentiation. J Neurochem 2011; 119:697-707. [PMID: 21668890 DOI: 10.1111/j.1471-4159.2011.07347.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dp71 has an important role in the central nervous system. To better understand the function of Dp71 domains in neuronal differentiation, PC12 cells were stably transfected with a dystrophin mutant, Dp71Δ(78-79) , which lacks exons 78 and 79. Based on the percentage of cells bearing neurites and neurite length analyses, we found that cells stably expressing Dp71Δ(78-79) (PC12-C11) differentiate more efficiently than non-transfected cells. While wild-type cells reach their maximum differentiation 9-12 days after initiating the differentiation process, the PC12-C11 cells reach differentiation in 4-6 days. Protein expression analysis showed a down-regulation of Dp71a and an up-regulation of Dp71ab and/or Up71, β-dystroglycan and neuron-specific enolase in undifferentiated and in neural growth factor differentiated PC12-C11 cells. No change was observed in the expression of Grb2 and Up400. The subcellular localization of Dp71Δ(78-79) was in the cell periphery, and there was no change in localization during the differentiation process, which was also observed throughout the neurite extensions.
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Affiliation(s)
- Jorge Aragón
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México, DF, México
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22
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Villarreal-Silva M, Centeno-Cruz F, Suárez-Sánchez R, Garrido E, Cisneros B. Knockdown of dystrophin Dp71 impairs PC12 cells cycle: localization in the spindle and cytokinesis structures implies a role for Dp71 in cell division. PLoS One 2011; 6:e23504. [PMID: 21886794 PMCID: PMC3158767 DOI: 10.1371/journal.pone.0023504] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2011] [Accepted: 07/18/2011] [Indexed: 12/22/2022] Open
Abstract
The function of dystrophin Dp71 in neuronal cells remains to be established. Previously, we revealed the involvement of this protein in both nerve growth factor (NGF)-induced neuronal differentiation and cell adhesion by isolation and characterization of PC12 neuronal cells with depleted levels of Dp71. In this work, a novel phenotype of Dp71-knockdown cells was characterized, which is their delayed growth rate. Cell cycle analyses revealed an altered behavior of Dp71-depleted cells, which consists of a delay in G0/G1 transition and an increase in apoptosis during nocodazole-induced mitotic arrest. Dp71 associates with lamin B1 and β-dystroglycan, proteins involved in aspects of the cell division cycle; therefore, we compared the distribution of Dp71 with that of lamin B1 and β-dystroglycan in PC12 cells at mitosis and cytokinesis by means of immunofluorescence and confocal microscopy analysis. All of these three proteins exhibited a similar immunostaining pattern, localized at mitotic spindle, cleavage furrow, and midbody. It is noteworthy that a drastic decreased staining in mitotic spindle, cleavage furrow, and midbody was observed for both lamin B1 and β-dystroglycan in Dp71-depleted cells. Furthermore, we demonstrated the interaction of Dp71 with lamin B1 in PC12 cells by immunoprecipitation and pull-down assays, and importantly, we revealed that knockdown of Dp71 expression caused a marked reduction in lamin B1 levels and altered localization of the nuclear envelope protein emerin. Our data indicate that Dp71 is a component of the mitotic spindle and cytokinesis multi-protein apparatuses that might modulate the cell division cycle by affecting lamin B1 and β-dystroglycan levels.
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Affiliation(s)
- Marcela Villarreal-Silva
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), México Distrito Federal, México
| | - Federico Centeno-Cruz
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), México Distrito Federal, México
- Laboratorio de Enfermedades Complejas, Instituto Nacional de Medicina Genómica, México Distrito Federal, México
| | - Rocío Suárez-Sánchez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), México Distrito Federal, México
- Departamento de Genética, Instituto Nacional de Rehabilitación, México Distrito Federal, México
| | - Efraín Garrido
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), México Distrito Federal, México
| | - Bulmaro Cisneros
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), México Distrito Federal, México
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Morales-Lázaro SL, González-Ramírez R, Gómez P, Tapia-Ramírez V, de León MB, Cisneros B. Induction of dystrophin Dp71 expression during neuronal differentiation: opposite roles of Sp1 and AP2alpha in Dp71 promoter activity. J Neurochem 2009; 112:474-85. [PMID: 19943855 DOI: 10.1111/j.1471-4159.2009.06467.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study, we delineated the molecular mechanisms that modulate Dp71 expression during neuronal differentiation, using the N1E-115 cell line. We demonstrated that Dp71 expression is up-regulated in response to cAMP-mediated neuronal differentiation of these cells, and that this induction is controlled at promoter level. Functional deletion analysis of the Dp71 promoter revealed that a 5'-flanking 159-bp DNA fragment that contains Sp1 and AP2 binding sites is necessary and sufficient for basal expression of this TATA-less promoter, as well as for its induction during neuronal differentiation. Electrophoretic mobility shift and chromatin immunoprecipitation assays revealed that Sp1 and AP2alpha bind to their respective DNA elements within the Dp71 basal promoter. Overall, mutagenesis assays on the Sp1 and AP2 binding sites, over-expression of Sp1 and AP2alpha, as well as knock-down experiments on Sp1 and AP2alpha gene expression established that Dp71 basal expression is controlled by the combined action of Sp1 and AP2alpha, which act as activator and repressor, respectively. Furthermore, we demonstrated that induction of Dp71 expression in differentiated cells is the result of the maintenance of positive regulation exerted by Sp1, as well as of the loss of AP2alpha binding, which ultimately releases the promoter from repression.
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Affiliation(s)
- Sara Luz Morales-Lázaro
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del I.P.N., Avenida Instituto Politécnico Nacional 2508, México, D.F., México
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24
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Dystrophin Dp71 is critical for stability of the DAPs in the nucleus of PC12 cells. Neurochem Res 2009; 35:366-73. [PMID: 19784870 DOI: 10.1007/s11064-009-0064-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2009] [Indexed: 10/20/2022]
Abstract
We have adopted the PC12 cell line as in vitro cell model for studying Dp71 function in neuronal cells. These cells express a cytoplasmic (Dp71f) and a nuclear (Dp71d) isoform of Dp71 as well as various dystrophin-associated proteins (DAPs). In this study, we revealed by confocal microscopy analysis and Western blotting evaluation of cell fractions the presence of different DAPs (beta-dystroglycan, beta-dystrobrevin, epsilon-sarcoglycan and gamma1-syntrophin) in the nucleus of PC12 cells. Furthermore, we established by immunoprecipitation assays that Dp71d and the DAPs form a dystrophin-associated protein complex (DAPC) in the nucleus. Interestingly, depletion of Dp71 by antisense treatment (antisense-Dp71 cells) provoked a drastic reduction of nuclear DAPs, which indicates that Dp71d is critical for DAPs stability within the nucleus. Although Up71, the utrophin gene product homologous to Dp71, exhibited increased expression in the antisense-Dp71 cells, its scarce nuclear levels makes unlikely that could compensate for Dp71 nuclear deficiency.
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25
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Qu J, Lin J, Zhang S, Zhu Z, Ni C, Zhang S, Gao H, Zhu M. HBV DNA can bind to P53 protein and influence p53 transactivation in hepatoma cells. Biochem Biophys Res Commun 2009; 386:504-9. [DOI: 10.1016/j.bbrc.2009.06.081] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Accepted: 06/15/2009] [Indexed: 11/28/2022]
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26
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Rodríguez-Muñoz R, Villarreal-Silva M, González-Ramírez R, García-Sierra F, Mondragón M, Mondragón R, Cerna J, Cisneros B. Neuronal differentiation modulates the dystrophin Dp71d binding to the nuclear matrix. Biochem Biophys Res Commun 2008; 375:303-7. [PMID: 18687308 DOI: 10.1016/j.bbrc.2008.07.135] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Accepted: 07/22/2008] [Indexed: 10/21/2022]
Abstract
The function of dystrophin Dp71 in neuronal cells remains unknown. To approach this issue, we have selected the PC12 neuronal cell line. These cells express both a Dp71f cytoplasmic variant and a Dp71d nuclear isoform. In this study, we demonstrated by electron and confocal microscopy analyses of in situ nuclear matrices and Western blotting evaluation of cell extracts that Dp71d associates with the nuclear matrix. Interestingly, this binding is modulated during NGF-induced neuronal differentiation of PC12 cells with a twofold increment in the differentiated cells, compared to control cells. Also, distribution of Dp71d along the periphery of the nuclear matrix observed in the undifferentiated cells is replaced by intense fluorescent foci localized in the center of the nucleoskeletal structure. In summary, we revealed that Dp71d is a dynamic component of nuclear matrix that might participate in the nuclear modeling occurring during neuronal differentiation.
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Affiliation(s)
- Rafael Rodríguez-Muñoz
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Avenida Instituto Politécnico Nacional 2508, Apartado Postal 14-740, C.P. 07360, México D.F., Mexico
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27
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Loss of neuronal projections in the dystrophin-deficient mdx mouse is not progressive. Brain Res 2008; 1224:127-32. [PMID: 18603229 DOI: 10.1016/j.brainres.2008.05.059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2008] [Revised: 05/14/2008] [Accepted: 05/17/2008] [Indexed: 11/22/2022]
Abstract
Lack of dystrophin is known to reduce several cerebral fiber systems. To investigate if the loss of fibers is progressive, we analyzed projections of the trigeminal sensory system to the red nucleus in 3, 6, and 12 month old dystrophin-deficient mdx mice. The retrograde tracer fluorogold was injected in the magnocellular part of the red nucleus, and the number of labeled neurons in the oral part of the spinal trigeminal nucleus (Sp5O) was counted. We found that the number of labeled Sp5O neurons was reduced by 50% in mdx mice compared to age-matched control mice. The number of labeled Sp5O neurons did not change significantly between 3 and 12 months neither in mdx nor in control mice. In addition, the number of labeled neurons in the interstitial system of the trigeminal nerve was reduced by 43% in mdx mice. We conclude that fiber loss did not continue beyond the age of 3 months. Our data suggest that lack of full-length dystrophin impairs neuronal migration or axonal outgrowth, or increases neuronal death during fetal or early life.
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28
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Liu X, Zhang S, Lin J, Zhang S, Feitelson MA, Gao H, Zhu M. Hepatitis B virus X protein mutants exhibit distinct biological activities in hepatoma Huh7 cells. Biochem Biophys Res Commun 2008; 373:643-7. [PMID: 18602370 DOI: 10.1016/j.bbrc.2008.06.087] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Accepted: 06/23/2008] [Indexed: 12/29/2022]
Abstract
The role of the hepatitis B virus X protein (HBx) in hepatocarcinogenesis remains controversial. To investigate the biological impact of hepatitis B virus x gene (HBx) mutation on hepatoma cells, plasmids expressing the full-length HBx or HBx deletion mutants were constructed. The biological activities in these transfectants were analyzed by a series of assays. Results showed that HBx3'-20 and HBx3'-40 amino acid deletion mutants exhibited an increase in cellular proliferation, focus formation, tumorigenicity, and invasive growth and metastasis through promotion of the cell cycle from G0/G1 to the S phase, when compared with the full-length HBx. In contrast, HBx3'-30 amino acid deletion mutant repressed cell proliferation by blocking in G1 phase. The expression of P53, p21(WAF1), p14(ARF), and MDM2 proteins was regulated by expression of HBx mutants. In conclusions, HBx variants showed different effects and functions on cell proliferation and invasion by regulation of the cell cycle progression and its associated proteins expression.
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Affiliation(s)
- Xiaohong Liu
- Department of Pathology, Changhai Hospital, Second Military Medical University, 174 Changhai Road, Shanghai 200433, PR China
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29
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Tie L, Zhang JZ, Lin YH, Su TH, Li YH, Wu HL, Zhang YY, Yu HM, Li XJ. Epinephrine Increases Phosphorylation of MAP-2c in Rat Pheochromocytoma Cells (PC12 Cells) via a Protein Kinase C- and Mitogen Activated Protein Kinase-Dependent Mechanism. J Proteome Res 2008; 7:1704-11. [DOI: 10.1021/pr700711s] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lu Tie
- Department of Pharmacology, School of Basic Medical Sciences and State Key Laboratory of Natural & Biomimetic Drugs, Peking University, Beijing 100083, China, Institute of Vascular Medicine, Peking University Third Hospital, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing 100083, P.R. China, and National Research Institute for Family Planning, Beijing 100081, P.R. China
| | - Jian-Zhao Zhang
- Department of Pharmacology, School of Basic Medical Sciences and State Key Laboratory of Natural & Biomimetic Drugs, Peking University, Beijing 100083, China, Institute of Vascular Medicine, Peking University Third Hospital, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing 100083, P.R. China, and National Research Institute for Family Planning, Beijing 100081, P.R. China
| | - Yan-Hua Lin
- Department of Pharmacology, School of Basic Medical Sciences and State Key Laboratory of Natural & Biomimetic Drugs, Peking University, Beijing 100083, China, Institute of Vascular Medicine, Peking University Third Hospital, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing 100083, P.R. China, and National Research Institute for Family Planning, Beijing 100081, P.R. China
| | - Tian-Hao Su
- Department of Pharmacology, School of Basic Medical Sciences and State Key Laboratory of Natural & Biomimetic Drugs, Peking University, Beijing 100083, China, Institute of Vascular Medicine, Peking University Third Hospital, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing 100083, P.R. China, and National Research Institute for Family Planning, Beijing 100081, P.R. China
| | - Yu-Hua Li
- Department of Pharmacology, School of Basic Medical Sciences and State Key Laboratory of Natural & Biomimetic Drugs, Peking University, Beijing 100083, China, Institute of Vascular Medicine, Peking University Third Hospital, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing 100083, P.R. China, and National Research Institute for Family Planning, Beijing 100081, P.R. China
| | - Hong-Li Wu
- Department of Pharmacology, School of Basic Medical Sciences and State Key Laboratory of Natural & Biomimetic Drugs, Peking University, Beijing 100083, China, Institute of Vascular Medicine, Peking University Third Hospital, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing 100083, P.R. China, and National Research Institute for Family Planning, Beijing 100081, P.R. China
| | - You-Yi Zhang
- Department of Pharmacology, School of Basic Medical Sciences and State Key Laboratory of Natural & Biomimetic Drugs, Peking University, Beijing 100083, China, Institute of Vascular Medicine, Peking University Third Hospital, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing 100083, P.R. China, and National Research Institute for Family Planning, Beijing 100081, P.R. China
| | - He-Ming Yu
- Department of Pharmacology, School of Basic Medical Sciences and State Key Laboratory of Natural & Biomimetic Drugs, Peking University, Beijing 100083, China, Institute of Vascular Medicine, Peking University Third Hospital, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing 100083, P.R. China, and National Research Institute for Family Planning, Beijing 100081, P.R. China
| | - Xue-Jun Li
- Department of Pharmacology, School of Basic Medical Sciences and State Key Laboratory of Natural & Biomimetic Drugs, Peking University, Beijing 100083, China, Institute of Vascular Medicine, Peking University Third Hospital, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing 100083, P.R. China, and National Research Institute for Family Planning, Beijing 100081, P.R. China
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Dp71, utrophin and beta-dystroglycan expression and distribution in PC12/L6 cell cocultures. Neuroreport 2008; 18:1657-61. [PMID: 17921863 DOI: 10.1097/wnr.0b013e3282f0e42d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Function of dystrophin Dp71 isoforms is unknown but seems related to neurite outgrowth and synapse formation. To evaluate Dp71 role in myoneural synapses, we established a coculture model using PC12 cells and L6 myotubes and analyzed expression and localization of Dp71 and related proteins, utrophin and beta-dystroglycan, in PC12 cells. Confocal microscopy showed Dp71d isoform in PC12 nuclei, golgi-complex-like and endoplasmic reticulum-like structures, whereas Dp71ab concentrates at neurite tips and cytoplasm, colocalizing with beta-dystroglycan, utrophin, synaptophysin and acetylcholine receptors. Evidences suggest that Dp71ab isoform, unlike Dp71d, may take part in neurite-related processes. This is the first work on Dp and members of Dp-associated protein complex roles in a cell-line based coculturing system, which may be useful in determining Dp71 isoforms associations.
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31
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Romo-Yáñez J, Ceja V, Ilarraza-Lomelí R, Coral-Vázquez R, Velázquez F, Mornet D, Rendón A, Montañez C. Dp71ab/DAPs complex composition changes during the differentiation process in PC12 cells. J Cell Biochem 2007; 102:82-97. [PMID: 17390338 DOI: 10.1002/jcb.21281] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PC12 cells express different Dp71 isoforms originated from alternative splicing; one of them, Dp71ab lacks exons 71 and 78. To gain insight into the function of Dp71 isoforms we identified dystrophin associated proteins (DAPs) that associate in vivo with Dp71ab during nerve growth factor (NGF) induced differentiation of PC12 cells. DAPs expression was analyzed by RT-PCR, Western blot and indirect immunofluorescence, showing the presence of each mRNA and protein corresponding to alpha-, beta-, gamma-, delta-, and epsilon-sarcoglycans as well as zeta-sarcoglycan mRNA. Western blot analysis also revealed the expression of beta-dystroglycan, alpha1-syntrophin, alpha1-, and beta-dystrobrevins. We have established that Dp71ab forms a complex with beta-dystroglycan, alpha1-syntrophin, beta-dystrobrevin, and alpha-, beta- and gamma-sarcoglycans in undifferentiated PC12 cells. In differentiated PC12 cells, the complex composition changes since Dp71ab associates only with beta-dystroglycan, alpha1-syntrophin, beta-dystrobrevin, and delta-sarcoglycan. Interestingly, neuronal nitric oxide synthase associates with the Dp71ab/DAPs complex during NGF treatment, raising the possibility that Dp71ab may be involved in signal transduction events during neuronal differentiation.
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Affiliation(s)
- J Romo-Yáñez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Avenida Instituto Politécnico Nacional 2508, Apartado Postal 14-740, C.P. 07000, Ciudad de México, México
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32
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Fuentes-Mera L, Rodríguez-Muñoz R, González-Ramírez R, García-Sierra F, González E, Mornet D, Cisneros B. Characterization of a novel Dp71 dystrophin-associated protein complex (DAPC) present in the nucleus of HeLa cells: members of the nuclear DAPC associate with the nuclear matrix. Exp Cell Res 2006; 312:3023-35. [PMID: 16824516 DOI: 10.1016/j.yexcr.2006.06.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Revised: 05/06/2006] [Accepted: 06/02/2006] [Indexed: 11/26/2022]
Abstract
Dystrophin is an essential component in the assembly and maintenance of the dystrophin-associated protein complex (DAPC), which includes members of the dystroglycan, syntrophin, sarcoglycan and dystrobrevin protein families. Distinctive complexes have been described in the cell membrane of different tissues and cultured cells. In this work, we report the identification and characterization of a novel DAPC present in the nuclei of HeLa cells, which contains dystrophin Dp71 as a key component. Using confocal microscopy and cell fractionation analyses, we found the presence of Dp71, beta-sarcoglycan, beta-dystroglycan, alpha- and beta-syntrophin, alpha1- and beta-dystrobrevin and nNOS in the nuclei of HeLa cells. Furthermore, we demonstrated by co-immunoprecipitation experiments that most of these proteins form a complex in the nuclear compartment. Next, we analyze the possible association of the nuclear DAPC with the nuclear matrix. We found the presence of Dp71, beta-dystroglycan, nNOS, beta-sarcoglycan, alpha/beta syntrophin, alpha1-dystrobrevin and beta-dystrobrevin in the nuclear matrix protein fractions and in situ nuclear matrix preparations from HeLa cells. Moreover, we found that Dp71, beta-dystroglycan and beta-dystrobrevin co-immunoprecipitated with the nuclear matrix proteins lamin B1 and actin. The association of members of the nuclear DAPC with the nuclear matrix indicates that they may work as scaffolding proteins involved in nuclear architecture.
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Affiliation(s)
- Lizeth Fuentes-Mera
- Department of Genetics and Molecular Biology, Centro de Investigación y de Estudios Avanzados del IPN, Avenida Instituto Politécnico Nacional 2508, Apartado Postal 14-740, C.P. 07000, México D.F., México
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Cerna J, Cerecedo D, Ortega A, García-Sierra F, Centeno F, Garrido E, Mornet D, Cisneros B. Dystrophin Dp71f associates with the beta1-integrin adhesion complex to modulate PC12 cell adhesion. J Mol Biol 2006; 362:954-65. [PMID: 16935300 PMCID: PMC1952692 DOI: 10.1016/j.jmb.2006.07.075] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2006] [Revised: 07/25/2006] [Accepted: 07/26/2006] [Indexed: 02/04/2023]
Abstract
Dystrophin Dp71 is the main product of the Duchenne muscular dystrophy gene in the brain; however, its function is unknown. To study the role of Dp71 in neuronal cells, we previously generated by antisense treatment PC12 neuronal cell clones with decreased Dp71 expression (antisense-Dp71 cells). PC12 cells express two different splicing isoforms of Dp71, a cytoplasmic variant called Dp71f and a nuclear isoform called Dp71d. We previously reported that antisense-Dp71 cells display deficient adhesion to substrate and reduced immunostaining of beta1-integrin in the cell area contacting the substrate. In this study, we isolated additional antisense-Dp71 clones to analyze in detail the potential involvement of Dp71f isoform with the beta1-integrin adhesion system of PC12 cells. Immunofluorescence analyses as well as immunoprecipitation assays demonstrated that the PC12 cell beta1-integrin adhesion complex is composed of beta1-integrin, talin, paxillin, alpha-actinin, FAK and actin. In addition, our results showed that Dp71f associates with most of the beta1-integrin complex components (beta1-integrin, FAK, alpha-actinin, talin and actin). In the antisense-Dp71 cells, the deficiency of Dp71 provokes a significant reduction of the beta1-integrin adhesion complex and, consequently, the deficient adhesion of these cells to laminin. In vitro binding experiments confirmed the interaction of Dp71f with FAK and beta1-integrin. Our data indicate that Dp71f is a structural component of the beta1-integrin adhesion complex of PC12 cells that modulates PC12 cell adhesion by conferring proper complex assembly and/or maintenance.
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Affiliation(s)
- Joel Cerna
- Departmento de Génética y Biologia Molecular
Centro de Investigacion y de Estufios Avanzados del I.P.N.Av. Instituto Politécnico Nacional 2508, Col. San PedroZacatenco, México, D. F. 07360,MX
| | - Doris Cerecedo
- Laboratorio de Hematologia
Escuela Superior de medecina y Homeopatia I.P.N.Wilfrido Massieu Helguera 239 Frac. La Escalera Ticomán. México, D. F. 07320,MX
| | - Arturo Ortega
- Departmento de Génética y Biologia Molecular
Centro de Investigacion y de Estufios Avanzados del I.P.N.Av. Instituto Politécnico Nacional 2508, Col. San PedroZacatenco, México, D. F. 07360,MX
| | - Francisco García-Sierra
- Deparmento de Biologia Cellular
Centro de Investigacion y de Estudios Avanzados del I.P.N.Av. Instituto Politécnico Nacional 2508 Col. San Pedro Zacatenco, México, D. F. 07360,MX
| | - Federico Centeno
- Departmento de Génética y Biologia Molecular
Centro de Investigacion y de Estufios Avanzados del I.P.N.Av. Instituto Politécnico Nacional 2508, Col. San PedroZacatenco, México, D. F. 07360,MX
| | - Efrain Garrido
- Departmento de Génética y Biologia Molecular
Centro de Investigacion y de Estufios Avanzados del I.P.N.Av. Instituto Politécnico Nacional 2508, Col. San PedroZacatenco, México, D. F. 07360,MX
| | - Dominique Mornet
- Muscles et pathologies chroniques
Université Montpellier I EA701Institut de Biologie, Boulevard Henry IV, 34062 Montpellier,FR
| | - Bulmaro Cisneros
- Departmento de Génética y Biologia Molecular
Centro de Investigacion y de Estufios Avanzados del I.P.N.Av. Instituto Politécnico Nacional 2508, Col. San PedroZacatenco, México, D. F. 07360,MX
- * Correspondence should be adressed to: Cisneros Bulmaro
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Calderilla-Barbosa L, Ortega A, Cisneros B. Phosphorylation of dystrophin Dp71d by Ca2+/calmodulin-dependent protein kinase II modulates the Dp71d nuclear localization in PC12 cells. J Neurochem 2006; 98:713-22. [PMID: 16893417 DOI: 10.1111/j.1471-4159.2006.03904.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We have shown that the splicing isoform of Dp71 (Dp71d) localizes to the nucleus of PC12 cells, an established cell line derived from a rat pheochromocytoma; however, the mechanisms governing its nuclear localization are unknown. As protein phosphorylation modulates the nuclear import of proteins, and as Dp71d presents several potential sites for phosphorylation, we analyzed whether Dp71d is phosphorylated in PC12 cells and the role of phosphorylation on its nuclear localization. We demonstrated that Dp71d is phosphorylated under basal conditions at serine and threonine residues by endogenous protein kinases. Dp71d phosphorylation was activated by 2-O-tetradecanoyl phorbol 13-acetate (TPA), but this effect was blocked by EGTA. Supporting the role of intracellular calcium on Dp71d phosphorylation, we observed that the stimulation of calcium influx by cell depolarization increased Dp71d phosphorylation, and that the calcium-calmodulin inhibitor N-(6-aminohexyl)-1-naphthalenesulfonamide (W-7) blocked such induction. The blocking action of bisindolylmaleimide I (Bis I), a specific inhibitor for Ca2+/diacylglicerol-dependent protein kinase (PKC), on Dp71d phosphorylation suggested the participation of PKC in this event. In addition, transfection experiments with Ca2+/calmodulin-dependent protein kinase II (CaMKII) expression vectors as well as the use of KN-62, a CaMKII-specific inhibitor, demonstrated that CaMKII is also involved in Dp71d phosphorylation. Stimulation of Dp71d phosphorylation by cell depolarization and/or the overexpression of CaMKII favored the Dp71d nuclear accumulation. Overall, our results indicate that CAMKII-mediated Dp71d phosphorylation modulates its nuclear localization.
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Affiliation(s)
- Luis Calderilla-Barbosa
- Genetics and Molecular Biology Department, Centro de Investigación y de Estudios Avanzados del IPN, San Pedro Zacatenco, Mexico
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Enríquez-Aragón JA, Cerna-Cortés J, Bermúdez de León M, García-Sierra F, González E, Mornet D, Cisneros B. Dystrophin Dp71 in PC12 cell adhesion. Neuroreport 2005; 16:235-8. [PMID: 15706226 PMCID: PMC2494584 DOI: 10.1097/00001756-200502280-00006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Previously, we reported that PC12 cells with decreased Dp71 expression (antisense-Dp71 cells) display deficient nerve-growth-factor-induced neurite outgrowth. In this study, we show that disturbed neurite outgrowth of antisense-Dp71 cells is accompanied by decreased adhesion activity on laminin, collagen and fibronectin. In wild-type cells, the immunostaining of Dp71 and beta1-integrin overlaps in the basal area contacting the substrate, but staining of both proteins decrease in the antisense-Dp71 cells. Morphology of antisense-Dp71 cells at the electron microscopic level is characterized by the lack of filopodia, cellular projections involved in adhesion. Our findings suggest that Dp71 is required for the efficient PC12 cell attachment to beta1-integrin-dependent substrata and that decreased adhesion activity of the antisense-Dp71 cells could determine their deficiency to extend neurites.
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Affiliation(s)
| | - Joel Cerna-Cortés
- Department of Genetics and Molecular Biology
Centro de Investigation y de Estudios Avanzados del IPNMX
| | - Mario Bermúdez de León
- Department of Genetics and Molecular Biology
Centro de Investigation y de Estudios Avanzados del IPNMX
| | | | - Everardo González
- Department of Genetics and Molecular Biology
Centro de Investigation y de Estudios Avanzados del IPNMX
| | - Dominique Mornet
- Muscle et pathologies
INSERM : ERI25IFR3Université Montpellier I : EA4202hopital arnaud de villeneuve
371, avenue du doyen gaston giraud 34295 Montpellier Cedex 05,FR
- * Correspondence should be adressed to: Dominique Mornet
| | - Bulmaro Cisneros
- Department of Genetics and Molecular Biology
Centro de Investigation y de Estudios Avanzados del IPNMX
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de León MB, Montañez C, Gómez P, Morales-Lázaro SL, Tapia-Ramírez V, Valadez-Graham V, Recillas-Targa F, Yaffe D, Nudel U, Cisneros B. Dystrophin Dp71 Expression Is Down-regulated during Myogenesis. J Biol Chem 2005; 280:5290-9. [PMID: 15550398 DOI: 10.1074/jbc.m411571200] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Dp71 expression is present in myoblasts but declines during myogenesis to avoid interfering with the function of dystrophin, the predominant Duchenne muscular dystrophy gene product in differentiated muscle fibers. To elucidate the transcriptional regulatory mechanisms operating on the developmentally regulated expression of Dp71, we analyzed the Dp71 expression and promoter activity during myogenesis of the C2C12 cells. We demonstrated that the cellular content of Dp71 transcript and protein decrease in myotubes as a consequence of the negative regulation that the differentiation stimulus exerts on the Dp71 promoter. Promoter deletion analysis showed that the 224-bp 5'-flanking region, which contains several Sp-binding sites (Sp-A to Sp-D), is responsible for the Dp71 promoter basal activity in myoblasts as well as for down-regulation of the promoter in differentiated cells. Electrophoretic mobility shift and chromatin immunoprecipitation assays indicated that Sp1 and Sp3 transcription factors specifically bind to the Sp-binding sites in the minimal Dp71 promoter region. Site-directed mutagenesis assay revealed that Sp-A is the most important binding site for the proximal Dp71 promoter activity. Additionally, cotransfection of the promoter construct with Sp1- and Sp3-expressing vectors into Drosophila SL2 cells, which lack endogenous Sp family, confirmed that these proteins activate specifically the minimal Dp71 promoter. Endogenous Sp1 and Sp3 proteins were detected only in myoblasts and not in myotubes, which indicates that the lack of these factors causes down-regulation of the Dp71 promoter activity in differentiated cells. In corroboration, efficient promoter activity was restored in differentiated muscle cells by exogenous expression of Sp1 and Sp3.
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Affiliation(s)
- Mario Bermúdez de León
- Department of Genetics and Molecular Biology, Centro de Investigación y de Estudios Avanzados del I.P.N., 07360 México
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